On 18 Jan 2002, Ulrich Drepper wrote:
> > But what about that Alpha's special code? It could possibly be
> > reused given the large Alpha's similarity to MIPS.
>
> No. Alpha has certain builtin code which looks similar to calls or
> software interrupts but are executed in the CPU. This allows access
Yep, PALcode is possibly the most significant difference.
> to some memory in the CPU which is almost as fast as a normal register
> access. MIPS doesn't have such hardware. If you cannot find a
> register you're doomed.
Hmm, why would an ABI reserve spare registers for a possible future use
that might never happen? We can probably define a new ABI specifically
for Linux, though, if the gain surpasses the loss.
--
+ Maciej W. Rozycki, Technical University of Gdansk, Poland +
+--------------------------------------------------------------+
+ e-mail: macro@ds2.pg.gda.pl, PGP key available +